Family Search records Dorcas Turner, b. 21 Nov 1741 in Newport, Charles, Maryland, as the daughter of Verlinda and Samuel Turner.
Maryland, Church Records, 1668-1995, database, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q298-982Q : 16 March 2018), Dorcas Turner, 21 Nov 1741; citing Birth, Newport, Charles, Maryland, United States, various libraries, churches, historical and national societies, private and public records; FHL microfilm 13,204.
Wikitree has an existing profile for Samuel Turner, Jr. and his wife Verlinda, whose maiden name is MacPherson. Click here: McPherson-1239
I've just sourced most of their children in Family Search and asked the two profile managers to add Dorcas as a child. I hope this helps!